Scanning tunneling microscopy and spectroscopy of wet chemically synthesized porous graphene nanoribbons on hydrogen passivated silicon (100)

This dissertation investigates wet-chemically synthesized atomically precise porous graphene nanoribbons (GNRs) exfoliated onto hydrogen passivated silicon H:Si(100) substrates using a dry contact transfer (DCT) method under ultrahigh-vacuum (UHV) conditions. The porous GNRs are characterized in UHV using scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). A unique electronic feature is observed at the pore sites in the STM topographic images. STS measurements indicate the presence of the pores significantly increases the bandgap compared to the surrounding GNR material. First-principles density functional theory (DFT) simulations are used to predict the band structure for the porous GNR. This is compared to theoretical simulations of the non-porous GNR case in order to elucidate how the addition of the pore to the GNR affects the electronic structure. Experimental results and first-principles computation modeling were shown to be in good agreement. Atomically precise GNRs with strategically placed pores expand the possibilities for applications in single-molecule detection and selectivity, including desalination and DNA sequencing.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2021

Author dc:creator

• Parsons, Kaitlyn Ann

Contributors dc:contributor

• Lyding, Joseph W
• Girolami, Gregory S
• Li, Xiuling
• Zhu, Wenjuan

• scanning tunneling microscopy
• scanning tunneling spectroscopy
• graphene nanoribbons
• hydrogen passivation
• silicon

Statement dc:rights

• Copyright 2020 Kaitlyn Parsons

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/109379

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/109379